Spectroscopy is a technique for measuring the concentration of organic and inorganic constituents of a solution. A common application of this technique occurs in the field of pulse oximetry. Pulse oximetry is the noninvasive measurement of the oxygen saturation level of arterial blood. Early detection of low blood oxygen saturation is critical because an insufficient supply of oxygen can result in brain damage and death in a matter of minutes. The use of pulse oximetry in operating rooms and critical care settings is widely accepted. Pulse oximeters generally include a light source and a detector. The light source transmits light (typically red and infrared light) through body tissue where it is attenuated by the tissue. The detector detects the attenuated light and sends a signal indicative of the detected light to a patient monitor for analysis.